A92/100
Rancho Santa Margarita Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 207,973 residents · California
What's In Rancho Santa Margarita's Tap Water?
76
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2009.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
SANTA MARGARITA WATER DISTRICT-ID9
Population Served
39,684
Water Source
Purchased Surface Water
System ID
CA3010030
SANTA MARGARITA WATER DISTRICT
Population Served
168,289
Water Source
Purchased Surface Water
System ID
CA3010101
Frequently Asked Questions About Rancho Santa Margarita Water
Is Rancho Santa Margarita tap water safe to drink?
Rancho Santa Margarita, California tap water receives a grade of A (92/100), which is considered excellent. Out of 76 contaminants tested, none exceed EPA maximum contaminant levels (MCLs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Rancho Santa Margarita's water?
76 contaminants were tested in Rancho Santa Margarita's water supply. No contaminants exceed EPA legal limits (MCLs) or health goals (MCLGs), which is a positive indicator of water quality.
Does Rancho Santa Margarita have any water quality violations?
Yes, Rancho Santa Margarita has 12 EPA violation(s) on record, with the most recent in 2022. Violation types include MR, MCL. 1 of these are health-based violations, which are the most serious category.
Do I need a water filter in Rancho Santa Margarita?
Rancho Santa Margarita water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. All contaminants are within health goals.
Where does Rancho Santa Margarita's tap water come from?
Rancho Santa Margarita's drinking water is sourced from purchased surface water and supplied by SANTA MARGARITA WATER DISTRICT-ID9 and 1 other water system(s). The system serves approximately 207,973 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Rancho Santa Margarita's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Rancho Santa Margarita's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Rancho Santa Margarita's water compare to other cities in California?
Rancho Santa Margarita's water quality score of 92/100 earns a grade of A, which is considered excellent. This places Rancho Santa Margarita among the better-performing water systems in California. Visit our California state page to see how all cities in the state compare.
What should I do if I'm concerned about Rancho Santa Margarita's water quality?
If you have concerns about Rancho Santa Margarita's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (SANTA MARGARITA WATER DISTRICT-ID9) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.